In the past, there have been an optical disc standard “BD-RE” in which a bluish-purple laser diode of 405 nm (hereinafter, inscribed as BD) is made to be a light source and it is possible to rewrite video, music, character data or the like massively on various discs so as to be standardized discs as recordable/reproducible discs, a playback-only optical disc standard “BD-ROM”, a write-once optical disc standard “BD-R” and the like, and in particular, in the standard of “BD-RE”, “BD-ROM” or the like, the disc thereof is known as a disc on which HDTV (high-definition television) is recordable/reproducible for two hours or more on one side of the disc thereof.
The 1-77PP [1-7 Parity Preserve/Prohibit RMTR (Repeated Minimum Transition Run Length)] which is used as a record coding system of data used in the above-mentioned standard is a system in which parameters of “d” limitation and “k” limitation are applied with 1 and 7 respectively in the encoding of RLL (Run Length Limited) and as the expression in NRZI (Non Return Zero Inverted), “d” and “k” limitations mean that the numbers “0” existing between “1” and “1” become a minimum value of “d” and a maximum value “k” respectively. Prohibit RMTR is a high density signal reproduction processing method and is a method for limiting repetition times the minimum run length in which it is constituted such that they are to be prevented from continuing seven times or more. Also, a Parity Preserve code is a code for realizing DC free and while insertion of a DC control bit is generally carried out after RLL encoding, it is inserted into a source bit string with respect to the Parity Preserve code before the RLL encoding and it is constituted such that conversion becomes possible by keeping the same parity when the source bit is RLL-encoded.
The bit rate of the 1-77PP modulation signal encoded according to the format of the 1-771-77PP system as mentioned above is made to be 66 MHz of the standard (one X speed) and 132 MHz of double speed. A digital processing—jitter analyzer which measures jitter of the 1-77PP modulation signal being compliant with the standard such as of “BD-RE”, [BD-ROM] or the like is disclosed in the Non-patent Document 1 (LEADER ELECTRONICS CORP. homepage, http://www.leader.co.jp, LE 1876, digital processing—jitter analyzer, 148 to 149, October 27, Heisei 15 (2003)). Also, with respect to the 1-77PP record encoding format using the above-mentioned 1-77PPrecord coding system, the present applicant disclosed a recording medium for heightening confidentiality of a unique ID in which a unique ID is recorded with respect to a BD disc in the Patent Document 1 (specification of Japanese patent application No. 2004-125893) and there is explained in detail also with respect to the 1-7 record encoding format therein.
Also, a software production system of an optical disc constituted such that a signal before being passed through a formatter of a disc such as a CD and data which are obtained by decoding a signal after being passed through the formatter are to be compared is disclosed in the Patent Document 2 (Japanese Unexamined Patent Publication No. 4-229461).
FIG. 11 shows a software production system 90 of an optical disc described in the Patent Document 2, wherein, in FIG. 11, there are constituted by a high capacity hard disk 92 recorded with software which converts source information of a computer 91, video, music, application program and the like to a predetermined recording format; a RAM 93 for storing software after the software recorded on the hard disk 92 is transferred; an FIFO 94 for adjusting transfer speed of the read out software according to the reproduction order read out from that RAM 93; and a CD-I player 95 for operating the software of this FIFO 94.
The aforesaid RAM 93 has recording capacity of at least the amount of CD-1 disc, for example, capacity of 640M bytes and it is constituted such that data of the amount of CD-1 disc transferred from the hard disk 92 are recorded therein. Also, the CD-1 player 95 is provided with a PC for executing an application of an EMF demodulator, its succeeding error detection, a video signal reproducing circuit or the like. More specifically, according to the software for carrying out conversion to the recording format recorded on the hard disk 92, the computer 91 converts the source information similarly recorded on the hard disk so as to become in conformity to with the CD-1 format.
In FIG. 11, the software recorded on the hard disk 92 is transferred to the RAM 93, and software is read out sequentially from the RAM 93 according to its reproduction order and read out sequentially from the FIFO 94. Reproduction signals which are synchronized with the reproduction of the CD-1 player 95 are outputted from this FIFO 94 and it is constituted such that a reproduction of music and video or execution of a program is to be carried out by the CD-1 player 95. In such a reproduction or an execution, if there is a problem in software which does not carry out evaluation of whether or not the software operates normally, it is constituted such that it is converted to a data format in conformity to with the CD-1 data format and operations for carrying out recording in the RAM 93 are to be repeated until the software comes to operate normally. Consequently, according to the described content of the Patent Document 2, there can be obtained a software production system of an optical disc in which time for evaluation necessary for writing-in software on a write-once optical disc at every time thereof as in a case in the past is shortened.
However, in the digital processing—jitter analyzer described in the Non-patent Document 1 mentioned above, it is directed to measure jitter of a HF 1-7 modulation signal of one X speed (66 MHz) and double speed (132 MHz), but not directed to carry out data check in real time with respect to high speed output data of a high capacity which are formatted on an occasion of BD-ROM recording.
Also, while it is possible to shorten processing time for converting music, video, application program or the like to the software in conformity with the CD-1 data format according to the constitution in the past described in the Patent Document 2 mentioned above, it is directed in the present invention to obtain a disc signal evaluation apparatus and a disc signal evaluation method in which it is possible to carry out a flexible data check in real time with respect to formatted high speed output data of a high capacity which are in conformity with a file system from the BD-ROM logic formatter in which data are recorded by the 1-77PPrecord coding system and the application system standard on an occasion of BD-ROM recording and also to carry out detection of an error by a noise in the BD-ROM logic formatter (signal generator) or the like.